Chair back supporting and adjusting mechanism



E. L. PERRY Dec. 27, 1955 CHAIR BACK SUPPORTING AND ADJUSTING MECHANISMFiled May 3, 1954 ELM/00D L. PEP/BY CHAIR BACK SUPPURTING AND ADJUSTlNGNIECHANISM Elwood L. Perry, Hickory,'N. C. Application May 3, 1954,Serial No. 427,260 Claims. (Cl. 155-456) The invention relates to chairsand similar articles of furniture having seats and backs, and it is moreparticularly concerned with improved mechanism for adjustably supportingthe chair back.

One object of the invention is to provide mechanism of the above generalcharacter which permits angular adjustment of the chair back through awide range, which is easily manipulable by a person sitting in the chairwithout rising therefrom, and which insures positive and rigid retentionof the chair back in anyselected position of adjustment.

Another object is to provide chair back supporting and adjustingmechanism which is very sturdy, which is simple and reliable inoperation and which can be manufactured at relatively low cost. I

Other objects and advantages of the invention will "become apparent fromthe following detailed description of the preferred embodimentillustratedin the accompanying drawing, in which:

Figure 1 is a side elevational 'view of a chair equipped with adjustableback supporting mechanism embodying the features of the invention.

Fig. 2 is a rear elevational view of the chair shown in Fig. 1.

Fig. 3 is -a sectional view taken in a'plane substantially on the line33 of Fig. 1 showing the latch means in latching position.

Fig. 4 is a sectional view similarto Fig. ,3 showing the latch meansactuated to release the chair back for.adjustment.

Fig. 5 is an exploded perspective view showing details of the latchmeans.

While a particular embodiment of the invention has been illustrated andwill be described herein, it -is .not intended to limit the invention.to details of the particular form shown but, on the contrary, theintention is to cover all modifications and adaptations falling withinthe spirit and scope of the invention as e resse'd in the appendedclaims.

Referring to the drawing, the invention'has been shown as incorporatedin an armchair for supportingthe back "B so that it may be angularlyadjusted relative to the seat S. The exemplary chair has a framecomprising a .pair of side assemblies connected by crossmembers .11which support the seat S, herein shown as'apad'orcushion 12. Additionalcross braces 13 may be provided below "the seat support forstrengthening the frame.

The side assembiles 10 are alike. As shown, eachcomprises a pair ofupright supporting elements .or legs 14 joined at their upper ends by atop member 15 appropriately shaped to constitute an arm rest. Additionalstructural members 16 and 17 extend between the 'legs 14 below andspaced from the arm rest, those members in the present instance beingparallel to the arm rest and rigidly attached to-the legs.

'The cha'irback B as showncomprisesa-pair'of side rails 18, a top rail'19 and a bottom rail 20 assembled and rigidly rjoined together to forma rectangular tramework.

tates PatentO This framework may be fitted with slats, webbing or othersuitable structurewhic'h'inay constitute a back rest or may serveas a'supportfor"'a-removable backrest, such as a pad or cujshionZl. Aswill'be seen .byrejference 'to Fig. '2o f the drawi g, the "backisdimensioned to fit between the'side assemblies 10 with suflicientclearance 'at each side to permit ittoswing freely.

In accordance with the invention, mechanism is pro vided for supportingthe chair back B on the frame so that it may be swung about a transversehorizontal axis into selected angular positions with respect to thechair seatand securelyiatched "in any selected position "of adlong, fiatendportionsESand justment. The supporting mechanism in its preferredform includes a pair of elongated side bars 25 and .26 of "steel orother suitable material adapted to have the upper end portions rigidlyattached to the side rails 18 of the chair back and to jgbe p'ivotajllymounted on the chair frame. The mounting ispreferably effected throughthe medium of "brackets '27 fastened to the frame side assemblies 10byscrew's .or other suitable fasteners.

The side bar 25, as shown, is formed with relatively 29 connected by anintermediate portion 30 bent at right angles to the end portions so thatthe latter are offset to lie-fin spacedparallel planes. The amount ofoffset .is suc'hithat when the end portion'28 is mounted :flush. againstthe side bar 18 of the chair back,the endportion'29 will extend alongthe outer side of the frame side assemblylt). For use with theparticular 'chair'illustrated, the upper end ofthe side bar 25'is angledslightly'with respect to the lower ,end portion 50 that the chair back.slopes rearwardly when the lower end portion is approximately upright.The side bar 26 is substantially a duplicate of the bar 25 except thatthe lower endportion 29/ is somewhatshorter than thecorrespondingportion of the companiouhar.

In the exemplary supportingmechanism, ,theside bars 25 and ,Zli'are,p'ivotally eonnected to their respective brackets 27 below thetransverse portions .30 of the bar h pi al c nn ction is provided by t asuitable pivot pin 31 which maybe in the form of va bolt or,rivet .thelatter being Preferredsin eiit permitsthe ,parts to be permanentlysecured together asa unit, thus precluding ,their separationandloss'before installation.

The brackets 27 7 preferably have their intermediate .portions offsetoutwardly from .theends to afford clearance for the side ba s. The ends.of the brackets .aresuitably apertured ,for the accommodation .of thefasteners by which they are attaehed'to the .chair frame. .In theexemplary embodiment, .the brackets .are :disposed diagonally 'acrossthe upper .rear corners of the frame ,side assembly .10 with their.ofisetrends attached respectively to .the arm .rest 15 and the rear.1eg..14. When :the arm rest '15 is relatively thick,-.as..sho.wn, itmay be formed with a recess 32 .adjacent therear .leg.14tso as .to clearthe intermediate portion of the side bar.

Attachment of the upper portionszsofthe side bars to .the .side mile 118ofithetchair back B ,may be effected in any preferred ,manner. .Asherein .shown, the .attaehment is by means .oftchannelrshaped :members133 screwed or otherwise pennanently If stened to the side rails 18 -soas to define elongated-sockets for slidably receiving he end portion of.theibars. .AfterassfimblL theparts may be locked'in assembled relationby screws .34 inserted through apertures in the channels :and threaded,into .the side lbars.

'The above described.mountingoflhechair.back B perrnits it to"beangularly adjusted .to the ,position most comfortable to the personsitting .inlhe chair and .without necessitating .rising from the chair.Theinvention also provides novel :latching means co-opera'ting withtthesupporting -struc'ture"for treleasably. retaining the chair backin anyselected-position 'dfadjustment.

The latching means in its preferred form comprises an elonga ed latchbar 35 pivotally connected adjacent its rear end as at 36 with theextended lower end portion of the side bar 25 and extending forwardlytherefrom as shown in Fig. l. Adjacent its forward end, the bar 35 has aseries of longitudinally spaced latching apertures 37 adapted to beslipped over a stationarily supported latch pin 38 (Figs. 3-5) carriedon the chair frame. As shown in Figs. 3 and 4, the pin 38 is rigidlyfixed to a mounting plate 39 adapted to be secured by screws or othersuitable fasteners to a suitable part of the chair frame, as forexample, the intermediate member 16 of the frame side assembly 10. Eachof the apertures 37 in the latch bar corresponds to a difierent angularposition of the chair back and the engagement of the pin in any apertureserves to positively retain the back in the corresponding position.

To prevent accidental disengagement of the latch bar, the latch meansincludes means for yieldably retaining the bar in engagement with thelatch pin, together with co-operating manually operable releasing meanswhereby the latch bar may be disengaged from the pin to permitadjustment of the chair back to a different position. The retaining andreleasing means is desirably incorporated in a unitary structure so thatthere are no loose parts that can be mislaid or lost before or afterassembly with the chair structure.

Referring to Figs. 3-5 of the drawing, the retaining and releasing meansin its preferred form includes a plunger 40 supported in axial alinementwith the pin 38 and urged by a spring 41 against the outer face of thebar 35. The plunger 40 is preferably formed with a head 42 forengagement with the bar and its shank portion is slidably received in anopening 43 in a stirrup-' shaped bracket 44 overlying the latch bar andthe pin 38. As shown in Figs. 3 and 4, the bracket 44 is riveted orotherwise rigidly attached to the pin mounting plate 39 and the biasingspring 41 is interposed between the bracket and the plunger head 42.

The latch releasing means comprises a lifting cam 45 interposed betweenthe mounting plate 39 and the latch bar 35 and rotatably supported onthe latch pin 38 for limited rotation about the axis of the pin. Camsurfaces provided on the cam 45 arearranged for coaction with the bar 35for shifting the bar axially of the locking pin to engage it with ordisengage it from the pin. In the exemplary mechanism a hand lever 46 isprovided on the cam for manual operation of the same, the hand leverbeing located for convenient access to a person sitting in the chair aswill be seen by reference to Fig. 1.

In the preferred form shown, the lifting cam 45 is of cup-shapeconstruction comprising a flat circular body member 47 with an integralupstanding rim 48 around its outer edge. The member 47 is centrallyapertured to fit over the pin 38 which serves as a pivot about which thecam may be rotated. As will be seen by reference to Fig. 5, the rim 48is cut away' or recessed at diametrically opposite sides of the body todefine a channel for the reception of the bar 35 which, when disposed inthe channel, lies flush against the outer face of the member 47. At oneside of each recess, the rim terminates in an upright shoulder orabutment 49 engageable with the side of the bar 35 to define one limitposition of the cam. This limit position is preferably such that thehand lever 46 extends substantially upright and is thus presented foreasy manipulation by the occupant of the chair.

At the other side of each recess, the rim 48 is sloped upwardly from themember 47 to define an inclined cam surface 50 effective upon rotationof the cam to shift the bar outwardly against the force exerted by thespring 41. It will be understood that the height of the rim 48 is suchthat the bar 35 may be shifted far enough to disengage it from the pin38.and thus free the bar so that it may be shifted endwise. Theprovision of the simultaneously acting cam surface 50 at opposite sidesor the bar precludes cocking or skewing of the bar as it is lifted offthe latch pin. Binding of the bar on the pin or at its connection withthe side bar 25 is thus avoided and smooth and easy operation of thelatch mechanism at all times is insured.

To facilitate adjustment of the chair back by a person sitting in thechair, provision is made for biasing theback to a substantially uprightposition. The biasing means preferably comprises a pair of coiledtensile springs 51 acting respectively between the side bars 25 and 26andthe chair frame. As shown, each spring 51 is anchored at one end tothe chair frame, in this instance, to the lower member 17 of the frameside assembly 10. At its other end, each spring is anchored to an arm 52rigid with and projecting forwardly from the respective side bars 25 and26 above their pivotal mounting on the chair frame. The arrangement issuch that upon'release of the latch mechanism, the chair back B willautomatically swing to an upright position unless opposed by forceexerted on it by a person sitting in the chair. e

To change the position of the chair back, that is, to adjust it to amore nearly horizontal position, it is only necessary for the occupantof the chair to move the hand lever 46 to the latch releaseposition andthen lean back in the chair until the chair back is pushed into thedesired angular position. Upon release of the hand lever the latchmechanism automaticaly re-engages to hold the chair back securely andpositively in the adjusted position. To adjust the chair back to a moreupright position, the occupant of the chair first leans back to relievethe pressure of the latch bar on the latch pin 38. The hand lever 46 isthen rocked to release position and, while held in such position,pressure on the chair back is gradually reduced. Springs 51 then act toswing the back toward upright position. Movement of the back can beinterrupted at any desired point by simply releasing the hand lever topermit the latch mechanism to re-engage. It will be evident from theforegoing that the chair back adjusting mechanism provided by thepresent invention is extremely easy to manipulate. The mechanism is verysturdy and the construction is simple so that it can be manufactured atlow cost. The mechanism is easy to install and it is readily applicableto a wide variety of chairs and similar articles of furniture equippedwith adjustable backs. i

I claim as my invention: 1. The combination with a chair having a framesupporting a seat and back, of mechanism for adjustably supporting theback on the frame comprising, in combination, a pair of elongated sidebars connectable respectively to opposite sides of the back, bracketsadapted to be rigidly attached to the frame at opposite sides thereof,means pivotally connecting said side bars to the respective brackets tosupport the chair back for swinging about a transverse horizontal axisadjacent the rear of the chair frame and the lower end of the back, oneof said side bars having its lower end portion extended a substantialdistance below said axis, a latch bar pivoted at one end to the extendedend of said side bar and projectingsaid pin, and cam means rotatableabout the axis of said I pin to shift said latch bar axially along andout of en-.

gagement with said pin to thereby release the chair back for, adjustmentto another position. 7

2. The combination with a chair having a frame supporting a seat andback, of mechanism for adjustably supporting the back on the framecomprising, in combination, a pair of elongated-side bars connectablerespec tively to opposite sides of the back, brackets adapted to berigidly attached to the frame at opposite sides thereof, means pivotallyconnecting said side bars to the respective brackets to support thechair back for swinging about a transverse horizontal axis adjacent therear of the chair frame and the lower end of the back, one of said sidebars having its lower end portion extended a substantial distance belowsaid axis, a latch bar pivoted at one end to the extended end of saidside bar and projecting forwardly therefrom along one side of the chairframe, a latch pin adapted to be mounted on the chair frame andprojecting therefrom transversely of said latch bar, said latch barhaving a series of apertures spaced apart longitudinally thereof forengagement selectively with said pin in different adjusted positions ofthe chair back, spring means yieldably urging said latch bar intoengagement with said pin, a cam member supported for rotation on saidpin, said cam member having a cam surface inclined with respect to saidlatch bar and coacting therewith when the cam member is rotated to shiftthe bar axially along the pin against the force exerted by said springmeans and out of engagement with said pin, and a hand lever for rotatingsaid cam member.

3. The combination with a chair having a seat frame and a back supportedthereon for angular adjustment about a transverse horizontal axisadjacent the rear of the frame, of latch means for retaining the chairback in selected positions of adjustment comprising, a latch bar adaptedto be connected to the chair back for endwise movement in a fore-and-aftdirection as the chair back is adjusted from one position to another, amounting plate adapted to be rigidly attached to the chair frame, a pinrigid with said plate and projecting therefrom transversely of saidlatch bar, said latch bar having a series of longitudinally spacedapertures for latching engagement with said pin, a bracket fixed to saidplate so as to overlie said pin and said latch bar, means including aspring interposed between said bracket and said latch bar yieldablyurging the latter into engagement with said pin, a cam member rotatablymounted on said pin between said plate and said latch bar, said camhaving a recess accommodating said latch bar and permitting it to engagesaid pin, and an inclined cam surface at one side of said recessoperative to shift said latch bar out of engagement with said pin uponrotation of said cam member, and a hand lever for rotating said cammember.

4. The combination with a chair having a seat frame and a back supportedthereon for angular adjustment about a transverse horizontal axisadjacent the rear of the frame, of latch means for retaining the chairback in selected positions of adjustment comprising, a latch bar adaptedto be connected to the chair back for endwise movement in a fore-and-aftdirection as the chair back is adjusted from one position to another, amounting plate adapted to be rigidly attached to the chair frame, a pinrigid with said plate and projecting therefrom transversely of saidlatch bar, said latch bar having a series of longitudinally spacedapertures for latching engagement with said pin, a bracket fixed to saidplate so as to overlie said pin and said latch bar, means including aspring interposed between said bracket and said latch bar yieldablyurging the latter into engagement with said pin,

cam means interposed between said plate and said latch bar for shiftingthe bar into and out of engaging relation to said pin, said cam meanscomprising a flat generally circular body centrally apertured forrotatable mounting on said pin, a rim upstanding from the edge of saidbody, said rim having recesses at diametrically opposite sides of saidbody dimensioned to receive said latch bar and allow it to lie inabutting relation to the body and in engagement with said pin, said rimat opposite sides of the respective recesses being formed to define anoutwardly sloping cam surface upon which said latch bar rides intodisengaged position with respect to said pin upon rotation of said body,and a hand lever for rotating said body.

5. The combination with a chair having a seat frame and a back supportedthereon for angular adjustment about a transverse horizontal axisadjacent the rear of the frame, of latch means for retaining the chairback in selected positions of adjustment comprising, a latch bar adaptedto be connected to the chair back for endwise movement in a fore-and-aftdirection as the chair back is adjusted from one position to another, amounting plate adapted to be rigidly attached to the chair frame, a pinrigid with said plate and projecting therefrom transversely of saidlatch bar, said latch bar having a series of longitudinally spacedapertures for latching engagement with said pin, a bracket fixed to saidplate so as to overlie said pin and said latch bar, means including aspring interposed between said bracket and said latch bar yieldablyurging the latter into engagement with said pin, cam means interposedbetween said plate and said latch bar for shifting the bar into and outof engaging relation to said pin, said cam means comprising a fiatgenerally circular body centrally apertured for rotatable mounting onsaid pin, a rim upstanding from the edge of said body, said rim havingrecesses at diametrically opposite sides of said body dimensioned toreceive said latch bar and allow it to lie in abutting relation to thebody and in engagement with said pin, said rim at opposite sides of therespective recesses being formed to define an out wardly sloping camsurface upon which said latch bar rides into disengaged position withrespect to said pin upon rotation of said body, said cam surfaces havinga slope such that the pressure exerted by said spring means through saidlatch bar is operative to turn said body into a position to aline therecesses with the latch bar, and manually operable means for rotatingsaid body in a direction to cam said latch bar out of engagement withsaid pin.

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